Soudal SWS Foam – Airtight Premium Window & Door Lo-expansion Acoustic Foam – Gun Grade

Soudal SWS Foam is a gun-grade, single-component polyurethane expanding foam built specifically for window and door installations where airtightness actually matters. Not every foam is equal in this department, and the SWS earns its place by meeting RAL MO-01/1 and DIN 18542 airtightness standards. If you’re fitting A, A+ or A++ rated windows and doors, this is the foam that keeps the certification meaningful once the frame is in.

The acoustic rating is worth paying attention to too. At 63 dB to ISO 717-1, there’s genuine sound-dampening performance here, not just gap-filling. Combined with a thermal conductivity of 34.5 mW/mK to DIN 52612, you’re getting solid performance on both fronts from a single product. That matters on new-build and retrofit jobs where installers are expected to hit energy performance targets.

What Makes Soudal SWS Foam Different From Standard PU Foam

The SWS uses Soudal’s FLEXIFOAM technology, which means once cured, the foam remains highly flexible rather than going brittle. Window and door frames move, especially timber ones, and a foam that can’t accommodate that movement will crack and fail over time. The flexibility here improves long-term durability and makes it a better fit for joints with repetitive movement or vibration.

Application is straightforward with a standard foam gun. The foam cures rapidly, adheres without primer on most common construction materials, and works across an application temperature range of -10 to +30°C. Linear yield is rated at 21 metres per can to FEICA TM1002, which gives a reasonable idea of coverage per can on a typical reveal.

A Note on Gun Grade

This is gun-grade foam, meaning it requires a foam applicator gun. It’s not a straw-can product. For anyone doing regular window and door work, a good foam gun pays for itself quickly in yield and control.